Diarrhea - Symptoms, Causes and Treatment

Diarrhea is the passage of 3 or more loose, watery stools per day. Whether acute or chronic, it is due to hypermotility of the colon or due to disturbances in fluid and electrolytes in the intestine. Much of the weight of a stool is made up of water. Thus, during the course of diarrhea, a lot of water is lost from the body. This is the reason why people get dehydrated during this illness. Diarrhea has many causes, and treatment lies in addressing the particular factor that is actually causing it.

Diarrhea can be acute, meaning that it lasts for a short duration of time (around 10 - 12 days), or chronic, which refers to diarrhea that does not get better for more than a month. A third type, called traveler's diarrhea, occurs to people who travel to places where diarrhea is endemic.

Acute diarrhea presents itself as clusters of symptoms, the main one being loose stools. These serve as pointers to the cause of a specific bout of diarrheal illness.

✓ Watery, loose stools, accompanied with a feeling of exhaustion.
✓ Presence of blood in stools.
✓ Watery diarrhea, accompanied with nausea and vomiting.
✓ Diarrhea within 10 - 12 hours of ingesting food.

✓ Abdominal pain and low-grade fever
✓ Passage of bloody stools or mucus in stools, along with a sense of urgency and pain in the rectum.
✓ High fever, abdominal pain, and rashes.
✓ Purpura, which is a discoloration of the skin so that it looks bruised, with purple blotches.

✓ Passage of small volume stools several times a day, with a constant feeling of urgency.
✓ Hypovolemic shock; this refers to a life-threatening emergency, in which loss of water from the body causes insufficient blood supply to the body.

Although there are several causes of acute diarrhea, a vast majority of individuals falling prey to it turn out to have recently acquired an infection by a disease-causing organism. Some of these are:

Bacteria: Several bacteria cause diarrhea, some cause only mild diarrhea, others can prove lethal. Some of these are: Vibrio cholerae, Escherichia coli, Salmonella, Campylobacter jejuni, Clostridium difficile, Shigella, Yersinia, Clostridium perfringens, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus cereus, Bacteroides fragilis, Aeromonas and Plesiomonas.

Viruses: Viruses are most active during the winters. Some cause severe diarrhea mostly in children, while some affect all age groups equally. The viruses causing diarrhea are: Rotavirus, Norovirus, Sapovirus, Adenovirus, Coronavirus, Cytomegalovirus (CMV) and Astrovirus.

Protozoa: Protozoa are very common causes of diarrhea in the developing countries. However, in developed countries, many protozoa are as prevalent - Giardia lamblia, Cryptosporidium, Entamoeba histolytica, Isospora belli, Cyclospora cayetanensis, Dientamoeba fragilis, and Blastocystis hominis.

• Ischemic colitis
• Infectious colitis
• Colonic diverticulitis
• Graft-versus-host disease
• Ingestion of toxins like organophosphate insecticides, Amanita mushroom, arsenic, toxins in seafood such as ciguatera and scombroid.

Fluid and Electrolyte Replacement Therapy: Since dehydration is an inevitable consequence of diarrhea, replacement of water and the electrolytes lost along with it is necessary in all cases. Oral rehydration solution (ORS) is given to the patient in most cases. The treatment, in rest of the cases, depends upon the degree of dehydration.

Mild Dehyderation
Adults: Fluids
Children: ORS (60 - 120 ml) *

Moderate Dehyderation
Adults: ORS
Children: ORS (50 - 100 ml/kg) **

Severe Dehyderation
Adults: Fluids & Electrolytes (I.V.)
Children: Ringer's lactate solution (I.V.) †

* If weight is less than 10 kg.
** Administered every 2 - 4 hours. 
† At a proportion of 100 ml/kg within 4 - 5 hrs.

Adults suffering from diarrhea can drink soups or consume other food products that have salt and sugar in moderate amounts. Commercially available juices are not recommended, because they may make the symptoms of diarrhea worse. Young children suffering from diarrhea should be breastfed or their normal diet should be continued.

However bad the symptoms might seem, the affected individual must not skip meals or refrain from eating. In case of children who have mild dehydration as well as constant bouts of vomiting, and if the vomiting shows no sign of stopping, then fluid and electrolytes by I.V. should be administered.

Young children who are severely dehydrated, and who are already being given fluid and electrolytes by I.V., should be put on ORS.

Antimotility Agents: These agents decrease intestinal motility, that is, they decrease the intestinal movements that propel the stool forward.

Loperamide, at a dose of 4 - 6 mg per day can be taken for mild traveler's diarrhea, but should be avoided completely in case of dysentery, and in case the diarrhea is a result of an inflammatory disease of the intestine.

Anti-secretory Agents: These agents temporarily correct the imbalance of electrolytes and fluid in the colon. Bismuth Subsalicylate is the antisecretory agent commonly used in diarrhea. Symptoms do get better with bismuth subsalicylate in both adults and children, but it cannot be used for all patients. It should be avoided in patients whose immune system is weak, and in those who are suffering from kidney damage.

Both the classes of drugs mentioned above should be avoided if the patient has fever along with the diarrhea.

Antimicrobial Agents: All drugs mentioned below are for adults. For children, the drugs may differ depending on the age. The dose for each drug varies depending upon the age group.

• Shigellosis: Ciprofloxacin is the drug of choice used for this infection. If it cannot be used, Pivmecillinam is the second line drug used.

• Cholera: Doxycycline or Tetracycline, both are the first choice for cholera. Azithromycin is the second choice.
• Amebiasis: Metronidazole is a highly effective treatment for amebiasis. However, after completion of a course of this drug, it is mandatory to take Diloxanide furoate for eradicating the amebial cysts.

• Giardiasis: Metronidazole is as effective for giardiasis as it is for amebiasis.
• Campylobacter: Azithromycin as a 3-day or 5-day dose pack is used to treat Campylobacter jejuni infections.

• Cryptosporidiosis: Nitazoxanide is the first choice for treating infections caused by Cryptosporidium. Other drugs used are atovaquone and paromomycin.

The symptoms are mostly the same as those given above for acute diarrhea. Some symptoms, like nausea, vomiting, fever, bloody stools (indicative of infectious causes) are usually not present in chronic diarrhea.

However, it does not mean that these have to be necessarily absent in cases of chronic diarrhea. The main difference is the duration of the condition, because diarrhea is considered chronic, if instead of resolving within a short period of time, it persists.

Diarrhea lasting for more than a month is generally considered as chronic diarrhea. The majority of the factors causing chronic diarrhea are non-infectious. However, many microbes that cause acute diarrhea are responsible for causing chronic diarrhea as well.

Intestinal Diseases and Conditions: A number of conditions involving the large and small intestine cause chronic diarrhea. Obstruction of any part of the colon, enterocolic fistula, fecal impaction, presence of diverticulum in the small intestine, stoma stricture and diseases of intestinal mucosa are all associated with diarrhea.

Chemicals: Habitual use of laxatives such as castor oil, senna, cascara, etc., osmotic laxatives and use of magnesium-containing antacids, all cause chronic diarrhea.

Tumors: A tumor in the gastrointestinal system as well as in distant parts of the body such as the lungs, cause chronic diarrhea. Some of these are: colorectal villous adenomas, gastrinoma, somatostatinoma, bronchial carcinoids, carcinoid syndrome, thyroid gland carcinoma, and gastrointestinal carcinoid tumors.

Inflammatory Disorders: Diseases in which the small or the large intestine gets inflamed are numerous. Inflamed intestines cannot function well enough to absorb nutrients properly. This results in chronic diarrhea.

Diseases like eosinophilic gastroenteritis, Behçet's syndrome, collagenous colitis, chronic ulcerative colitis, lymphocytic colitis, celiac disease, and Crohn's disease can cause diarrhea.

Surgery: Surgical procedures of the colon resolve the problem that the surgery is aimed at, but unfortunately end up causing problems of their own. Chronic diarrhea may develop after having surgeries like bowel resection and removal of the gallbladder.

Disorders of Malabsorption: The intestinal absorption of certain foods may become impaired due to various factors resulting in chronic diarrhea. Malabsorption of bile acids, malabsorption of certain carbohydrates, Whipple's disease (a disorder in which the small intestine is unable to absorb nutrients) end up causing chronic diarrhea.

Genetic Disorders: People with genetic disorders like congenital chloridorrhea and systemic mastocytosis often have chronic diarrhea. In these cases, symptomatic treatment is the only choice available to the patient.

Pancreatic Disorders: The pancreas secrete insulin and other hormones as well as pancreatic juice for the digestion of food. They are prone to a number of conditions like duct obstruction, pancreatic cholera and exocrine insufficiency, that take a toll on the rest of the body as well.

Hormonal Disorders: Conditions associated with hormonal imbalance have far-reaching effects on all systems of the body, including the intestines. In diseases like Addison's disease and hyperthyroidism, resolving the hormonal imbalance is the key to treating the chronic diarrhea associated with them.

• Abetalipoproteinemia
• Biliary obstruction
• Amyloidosis
• Cronkhite-Canada syndrome
• Immunodeficiencies
• Visceral neuromyopathies
• Lymphatic obstruction
• Diarrhea associated with diabetes

The treatment of chronic diarrhea depends upon addressing the specific condition that is causing it. Usually, as in the above cases, the diarrhea is one of the manifestations of some primary condition. If it is not possible to permanently resolve the condition, symptomatic treatment of diarrhea associated with it is resorted to.

This term is used when diarrhea is acquired by people traveling to certain regions where a certain bacterium, virus, or other pathogen is commonly present, and a significant percentage of the population has diarrhea. Many organisms cause traveler's diarrhea.

The most common one is 'Giardia lamblia'. People pick up this parasite by contaminated food and water, and is especially seen while picnicking in the wild. Many other microbes cause traveler's diarrhea, like enterotoxigenic Escherichia coli, norovirus, and many other microbes.

Diarrhea is an exceedingly common condition, and like many other such conditions, can be really annoying if it turns chronic. Acute diarrhea though, can be prevented in most cases, by simply taking care to avoid contaminated food and water.

Disclaimer: This story is for informative purposes only, and should not be used as a replacement for medical advice.